1. Field of Invention
The present invention relates generally to the field of memory allocation and organization in relational databases. More specifically, the present invention is related to reorganizing object memory and increasing page size allocations.
2. Discussion of Prior Art
As is commonly defined in database applications, a database consists of sets referred to and displayed as tables. In turn, tables consist of records which are referred to and displayed as rows of a table. Lastly, each row consists of individual data fields known as columns. As data fields, rows, and columns are added and deleted from tables, the probability increases for data that is logically sequential in nature to be stored on pages that are physically non-sequential. This leads to sub-optimal performance, as additional read operations become required to access non-sequentially stored data. As tables are updated with deletions and insertions, performance degradation also occurs through the fragmentation of leaf pages, badly clustered indices (i.e. when the physical index page no longer matches the sequence of keys on a current page), and an index developing a less than optimally efficient number of levels. Fragmentation of leaf pages leads to increasing input/output (I/O) costs as more leaf pages must be read to fetch pages corresponding to a single, designated table. Additionally, when leaf pages are badly clustered, sequential pre-fetching is inefficient and results in more I/O waits.
Furthermore, when an object is created in a database, the page size allocated for the object is chosen as well. As the object increases with size, either through the addition of columns or rows, the initially allocated page may no longer be adequate to store the entire object. As a result, it is frequently necessary to re-allocate a page of appropriate size for a table. Re-allocation of a page requires unloading and reloading data from each individual data field in the table, making new image copies of the table, and re-granting previous authorizations. While these operations are in progress, the table object is unavailable for substantial periods of time.
Prior art attempts of changing an initially allocated page size are recited in patent literature. U.S. Patent application publication 2003/0115220 teaches the editing of a production data store by shadowing content. In this method, changing a page size changes the production data store by making a shadow the permanent production data store and also updating the databases control blocks to reflect the new page size. However, this method is limited in that only the shadow is modified; no change is made to the permanent production data store.
International patent application publication WO 02/098048 discloses a method for performing an online reorganization of a database. However, the method is limited in that it does not describe changing the attributes of the physical object.
U.S. patent application publication 2003/0130985 discloses a method for upgrading a database with a shadow system. This method references two separate systems operated in parallel; the shadow system is updated via trigger reports from the main system. The method for changing page size only works on a single system. Processing occurs on an original page set in the main system until a switch to the shadow system occurs. Therefore, if updates are allowed during the reorganization process, then both original page set and shadow are updated.
As is shown, prior methods of changing page size fail to teach or suggest a method for dealing with the problems and performance degradation associated with fragmentation and badly clustered indices.
Whatever the precise merits, features, and advantages of the above cited references, none of them achieves or fulfills the purposes of the present invention.